1. Field of the Invention
The present invention relates to an electrostatic latent image-developing toner.
2. Description of the Related Art
An emulsified dispersion method has been conventionally known as one of methods for producing resin particles. In such a method, a resin solution obtained by dissolving a resin in a non-aqueous organic solvent is emulsifiedly dispersed in an aqueous medium to form an emulsion, and the emulsion is heated under continuous stirring to remove the organic solvent by allowing it to evaporate, whereby resin particles are obtained. According to the emulsified dispersion method, polymer fine particles having a mean particle size of about 1 to 10 .mu.m can be obtained with a comparatively easy operation simplifying a process, so that the emulsified dispersion method can improve a production efficiency and, at the same time, cost reduction as compared to a pulverization method and a suspension polymerization method. Further, the number of kind of resin usable in the emulsified dispersion method is more than that in the suspension polymerization method and the like.
Accordingly, it is expected that, if such a emulsified dispersion method is put into practical use to blend toner components, such as a colorant, a charge control agent and a magnetic powder, into the resin solution, an electrostatic latent image-developing toner answering needs with respect to fields of a coping machine and a printer in an electrophotograghic system, such as high speed, high picture quality and coloration, can be comparatively easily obtained at a low price. For example, Japanese Patent Application Laid-Open Nos. 91,666/1986 and 25,664/1988 disclose a manufacturing method for an electrostatic latent image-developing toner, in which the emulsified dispersion method is applied.
However, the toner obtained by the emulsified dispersion method has many air caves inside, because water is easily taken into an oily droplet in O/W type emulsion at a step for emulsifiedly dispersing. Therefore, there is the problem that a chargeability changes easily due to a change of surrounding environments and imaging properties tend to be adversely affected.